2-amino-4-nitrophenoxypropandiol and process of producing same



Patented May 22, 1928.

UNITED STATES PATENT OFFICE.

OSCAR KNECHT, OF IBINNINGEN, NEAR BASEL, SWITZERLAND, ASSIGNOB TO THE FIRM CHEMICAL WORKS FOBHERLY SANDOZ, OF BASE L, SWITZERLAND.

2-AMINO-4-NITROTHENOXYPROPANDIOL AND PROCESS bl PRODUCING SAME.

' Ho Drawing. Original application filed December 13, 1926, Serial No. 164,852, and in Germany December 19, 1925. Divided and; this application flied October 27, 1827, Seriai No. 229,275.

This application is divisional of application Ser. N 0. 154,652, filed December'13, 1926.

2.4-dinitrophenoxypropandiol is, contrarily to the 2.4-dinitrophenolalkylethers,

5 easily hydrol zed by alkaline agents, as for instance by dilute caustic soda. This splitting off of the glycerol radical, which happens very easily, is the reason why the preparation of this com und, after known prescriptions, could hit erto only be per-' formed in an imperfect manner. It was, therefore, not to be foreseen, whether it would be possible to transform the 2.4-dinitrophenoxypropandiol into the hitherto unknown nitroamino compound by means of alkaline reducing agents. w

' It has now been found that this is ossible and almost without saponification, i 2-.4-dinitrophenox propandiol is treated with alkali sulphi es or alkali polysulphides at warm temperature. By an easy reaction. and without by-products, 2-amino-4-nitrophenoxypropandiol'is formed, which is more difiicultly saponifiable than the dinitrocom- 2 pound. This derivative of m-nitraniline,

which so far as known has never been repared, may be used as intermediate pro net for the preparation of valuable-dyestufisi The following example illustrates the :0 process: p

To an aqueous suspension of 200 kg of 2.4-dinitrophenoxypropandiol (Berliner Berichte 12, 766; Journ. Chem.- Soc. London,

119, 1035 an aqueous solution of sodium tetrasulfi e, repared from 240vkg of-sodium sulphide and 96 kg of sulphur, is added, under vigorous stirring at about 60' 6., whereby an immediate reduction takes place under self heating. The mixture is kept a 40 short time at a temperature of 60 0., then cooled down to 20 C, After neutralization with 25. kg of hydrochloric acid the nitroaminocompound is precipitated as an orange colored deposit containing sulphur. The

4 nitroaminocompound is then dissolved in 500 litres oi water and 80 kg of hydrochloric acid, the sulphur remaining undissolved. The hydrochloride solution can be.used as such, or the base can be precipitated with soda.. In the latter case the base separates as a brown oil, which solidifies by stirrin to a golden-yellow crystalline deposit. The

hitherto unknown 2-amino-4-nitrophenoxypro andiol forms, recrystallized from water,

gol en-yellow crystals, melting at 114 C.; it is easily soluble in alcohol and very diflicultlyv soluble in benzene. It dissolves easily in dilute mineral acids; the solutions thus obtained can be quantitatively diazotized whereby clear diazo solutions are formed.

The working conditions are not limited to those of the above example, but may be varied to a large extent. For instance, the dinit-rocompound may be added to the reduc-' ing agent or the reaction may be performed in an aqueous a-lcoholic'or a pure alcoholic solution. Further the reduction can also take place at other temperatures and wit-h other polysulphides and other quantities of these agents.

What I claim is:

1. A process for the preparation of 2- amino-4-nitrophenoxypropandiol, consisting 'in treating 2.4-dinitrophenoxypropandiol with analkali sulphidejis reduclng agent. 2. A process for the pre aration of 2- amino-i-nitrophenoxypropan iol, consisting in treatin QA-dinitrophenoxypropandiol with an kali polysulphide as reducing agent. a 3. The herein described 2-amino-4-nitrophenoxypropandiol, obtained by the treat ment of 2.4-dinitrophenoxypropandiol with alkali sulphides and constituting an inter mediate product for dyestuffs 1n form of yellow crystals easil soluble in alcohol and very diflicultly solub e in benzene, dissolving easily in dilute mineral acids to quantita- -tively diazotizable solutions In witness whereof I have hereunto signed iny name this 14th day of October, 1927.

' QSCAR KNECHTJ 

